The document discusses best practices for airflow management in computer rooms and data centers. It identifies two types of computer rooms - those without and with intake air temperature problems for IT equipment. Improving airflow management (AFM) can solve intake air issues to make facilities more efficient. The document also discusses concepts like bypass airflow, recirculation, and the benefits of proper cable penetrations and containment. It provides examples of how AFM practices applied incorrectly can negatively impact cooling and presents strategies like Upsite's 4 R's methodology to optimize airflow.

1. The Science Behind Airflow
Management Best Practices
Lars Strong, P.E., Upsite Technologies
Mark Seymour, Future Facilities
Airflow Management Awareness Month
June 1, 2016

2. Identify Your Opportunity
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There are two types of computer rooms
1. Those without IT equipment intake air temperature problems
• Improving AFM enables them to be more efficient
2. Those with IT equipment intake air temperature problems
• Improving AFM solves intake air temperature problems (hot
spots and cold spots) and enables them to be more efficient
• More efficient results in: lower OPEX, deferred CAPEX,
increased cooling capacity

3. Why Airflow Management
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Total Load
IT Load
PUE =
Mechanical plant +
cooling fans: 35%
of total load, 73%
of non IT Load

4. BYPASS AIRFLOW CLARIFIED
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5. Definition of Bypass Airflow
Any cooling air that does not pass through IT
equipment before returning to a cooling unit
Bypass flow rate (CFM) = total cooling supply
flow rate (CFM) – total IT equipment flow rate
(CFM)
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6. ΔT Through IT Equipment
UPS load (kW) x avg CFM/kW = Total IT CFM
IT Equipment Required Flow Rate
IT
Equipment
Delta T
(deg F)
15° 20° 25° 30° 35° 40°
Required
flow rate
(CFM/kW)
211 158 126 105 90 79
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7. Bypass Airflow Clarified
Typical existing conditions
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8. Bypass Airflow Clarified
After AFM improvements
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9. Bypass Airflow Clarified
Optimized
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10. Upsite’s 4 R’s of Airflow Management™
 A holistic approach
 An iterative process
 ‘check in’ at the room level
after making any
adjustments
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Watch video at:
upsite.com/resources/airflow-management/
© Upsite Technologies, Inc.

11. Airflow Management Best Practices
Gone Wrong, What We Can Learn
Mark Seymour
Future Facilities 11

12. This presentation illustrates some of the classic actions in a
data center that can create airflow management issues
The intent is to reveal:
• Why considering airflow is important
• That good practice is just that – it’s not a guarantee
• Engineering simulation is used to illustrate airflow that is
otherwise unseen and enabling proactive operational
management
• Airflow management applies to both the rack/cabinet level
and the room level
Introduction
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Energy efficiency of the
cooling system can be
undermined by
• Negative flow 
o Often through perforated tiles
near the cooling unit
• By-pass
o Can overshoot IT or pass
through unmanaged leakage.
E.g. cable penetrations
• Recirculation 
o Occurs in the rack as well as
the room is important
Common issues
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14. CABLE PENETRATIONS & LEAKAGE
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 Unmanaged cable
penetrations
 Typically installed in
raised floor in rear if the
cabinet
 Installing cable
management is an easy
win but care should be
taken to ensure the
cooling is not in use
Leakage Paths
 Watch for leakage paths
• Under the cabinet
• Over the cabinet (through
containment)
• Between cabinets
• End of rows (through
containment)
• Through Cooling Units on
standby
• Similarly in the rack
o Under
o Over
o Between
o Around equipment
o Through IT equipment that is
off
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Cable Penetration Seals
Cable Penetration Management
 Why practice it?
• Stop air leaking out of the
cable penetrations
• Increase the pressure in
the raised floor plenum
• Stop bypass cooling down
the hot return air
• Force more air out of the
perforated tiles and grates
in front of the IT
equipment
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 Hot Aisle / Cold
Aisle
 Mix of Equipment
 Size: 1,066 sq. ft.
 Cooling: 55.6 tons
(196 kW)
 Load: 152 kW
Example Room
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ASHRAE Temperature Compliance
One rack has inlet temperatures above the ASHRAE
Temperature Compliance recommended range
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19. Using simulation we can investigate the impact of adding
brush seals to the cable penetrations:
Modeling of Penetration Seals
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Static Pressure
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Perforated Tile Flow
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ASHRAE Temperature Results
Comparison
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Improving raised floor open area
management reveals need to improve
rack airflow management

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Why Did the Room Get Worse?
With Brush
Seals
No Seals
Improving rack airflow management with blanking
panels, rail seals, and under rack panels will bring IT
intake air temperatures back into compliance
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 Sealing holes in the floor are still the best practice
 It is critical to apply best practices to sealing the
cabinet at the same time.
 Final engineering simulation image would reveal
optimized cooling with no exhaust air recirculation
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Equipment Configuration
Consider a cabinet housing
a blade system and 3 1U
servers
• Does it matter how the 2
equipment types are
installed in this cabinet?
• Option 1 – Three 1U
servers placed on top of a
BladeCenter H
3kW Blade
Enclosure
3 x 1U 275W
Servers
15o
C / 59°F Supply Air
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Equipment Configuration
Base Configuration – Option 1
Recirculation
under cabinet
Maximum inlet temperature
o
C (°F)
Blade 27.1 (80.8)
Server1 19.6 (67.3)
Server2 19.7 (67.5)
Server3 18.9 (66.0)
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Equipment Configuration
Option: 1U servers under blade
Maximum inlet temperature
o
C (°F)
Blade 18.1 (64.6)
Server1 19.1 (66.4)
Server2 20.9 (69.6)
Server3 21.8 (71.2)
Recirculation from
1u servers is cooler
Recirculation of this nature can occur
whether or not the data center is
contained. The solution is blocking the
under rack airflow.
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28. AISLE CONTAINMENT
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Consider two rows of equipment with full cold aisle
containment:
Cold Aisle Containment
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Containment Measured
Warmer Air
Supply
No change
Colder Air
Supply
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 Simulation shows what is
happening:
• There is a lack of available
airflow
• Uncontained, the
additional air required
recirculates via the room
over the top of the
cabinets. Consequently it
mixes and so is colder
than the air in the hot aisle
• Contained, the additional
air recirculates directly
from the back of the
cabinets and, without any
mixing, it is hotter.
Simulation Explains All
Uncontained
Contained
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32. COOLING UNITS
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 More efficient (up to 30%)
 Easily controlled (0-10V
signal)
 Longer life and reduced
maintenance
 Improved airflow through
the CRAC/CRAH
 Reduced noise
Benefits of EC fans?
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Air Distribution
EC Plug Fans vs Traditional Blowers
Blower
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35. Traditional BlowersLowered EC Plug Fans
The different types of fans distribute air in different ways
The Effect on Airflow
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 6,727ft² of floor space
 200+ Cabinets
 800kW Cooling Capacity at
N+2
Test Facility
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37.  Airflow distribution patterns look very different.
 How has this affected the available cooling?
Grille Flow
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38. 0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10 11 12 13
PotentialCooling(kW)
Cold Aisle
Cooling Available per Row
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39. Reduced cooling capacity puts IT at risk of thermal
shutdown
Immediate Issues
Aisle 4 cooling
reduced 21kW
64 Blades now at
risk
Aisle 5 cooling
reduced 15kW
30 Proliants now at
risk
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40. Immediate Issues
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Upsite's 4 R's of Airflow Optimization provide a guide for
implement changes and achieving the greatest benefits in
your data center.
“Efficiency can’t be purchased,
it has to be managed”
Julian Kudritzki
- The Uptime Institute

41.  Airflow management is essential for optimizing capacity
and efficiency of the entire data center
 Good practices are often beneficial but should be
undertaken with due diligence
 Airflow is invisible, therefore the hardest thing to manage
in a data center
 Actions for one scenario may be beneficial while in
another counter productive – e.g. total containment in an
over-provisioned scenario compared with an under-
provisioned scenario.
 Engineering simulation can visualize and help guide
airflow management choices
 Apply the 4 R’s Methodology to Airflow Management
Summary & Conclusions
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42.  June 8: 5 Myths of Data Center Containment
Presented by Lars Strong, P.E.
 June 15: How IT Decisions Impact Facilities: The
Importance of Mutual Understanding
Presented by Ian Seaton and Lars Strong, P.E.
 June 22: The 4 Delta T’s of Airflow Management
Presented by Lars Strong, P.E.
 Register at upsite.com/airflow-management-awareness-
month
Upcoming Schedule
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43. Thank you!
@UpsiteTech
blog.upsite.com
On LinkedIn
Lars Strong, P.E.
Senior Engineer, Upsite
Technologies
lstrong@upsite.com
Follow Upsite for the latest
news and information on
data center AFM.
Mark Seymour
Senior Engineer, Future
Facilities
Mark.Seymour@futurefacilities.com